فهرست مطالب

  • Volume:5 Issue: 2, 2018
  • تاریخ انتشار: 1397/09/24
  • تعداد عناوین: 6
|
  • Horieh Moosavi, MohammadJavad Moghaddas, Fatemeh Kordnoshahri, Maryam Zanjani Pages 544-550
    Statement of Problem: The integrity of adhesive bond at the tooth/resin interface performs an essential role in the clinical success and survival of restorations.
    Objectives
    The purpose of this study was to compare microleakage of Class II cavities restored with total-etch or self-etch adhesives and different bulk-fill composites.
    Materials and methods
    Conventional class II cavities were prepared on fortysound human premolar teeth with approximately same size and shape. Half of the cavities restored with a sonic-resin placement system (SonicFill, Kerr), and the other half of the cavities with Tetric N-Ceram (TNC) composite with total-etch; Optibond Solo Plus or self-etch; Optibond XTR, adhesives. The samples stored in distilled water at 37 ° C for 24 hours, and then specimens were under 1000 thermal cycles. The teeth were covered with two layers of nail varnish except for one mm around gingival margins, and then were dipped in glass vials for 48 h at 37°C in a neutral-buffered 2% methy leneblue solution. After removal from the dye, the teeth were rinsed and the varnish was removed, and stored individually in a glass vial containing 65%
    nitric acid. The vials were centrifuged, and 100 μl of the super natant from each was then analysed in a UV-Visible spectro photometer after a kinetic assay at 550 nm wavelength using concentrat ed nitric acid as the blank. So dye extraction was conducted to investigate the leakage test. Data were analysed by ANOVA test (P<0.05).
    Results
    The highest and lowest microleakage was related to self-etch SonicFill and total-etch/Tetric N-Ceram groups respectively. The amount of microleakage was not significantly different among experimental groups (P>0.05).
    Conclusions
    Both of the bulk-fill composites with various adhesives had the same microleakage
    Keywords: Bulk fill, Adhesive resin , Microleakage , Dye extraction
  • Hüseyin Sinan TOPCUO?LU, ?brahim ?ENER, Sezer DEM?RBU?A, Nazire Nurdan CAKIR, Gamze TOPCUO?LU Pages 551-558
    Statement of problem: Safe and efficient removal of all root filling materials from the canal system is essential for optimal nonsurgical retreatment, because it provides effective cleaning, shaping, and re-filling of the root canal system.
    Objectives
    This study compares the effectiveness of Reciproc Blue, HyFlex CM, Reciproc, and ProTaper Universal retreatment files (PTUR) in removing root canal filling material (RCFM).
    Materials and methods
    Sixty human upper central incisors were shaped with Revo-S files up to apical size 40 and were obturated using the cold lateral compaction technique. After two weeks, the RCFMs were removed with Reciproc Blue, HyFlex CM, Reciproc, or PTUR (ProTaper Universal Retreatment) files. Teeth were cleaved longitudinally, and digital images were then captured. The amounts of RCFMs in the obtained images were analyzed using ImageJ software, and the time required to remove the RCFM was recorded. Data were analyzed using a one-way of variance (ANOVA) test.
    Results
    There was no significant difference among the files in the coronal third (P>0.05). In contrast, in the middle and apical thirds, the amount of remaining
    RCFM was significantly higher in HyFlex CM and Reciproc Blue groups than that of PTUR and Reciproc groups (P<0.05); however, there is no significant difference between the HyFlex CM and Reciproc Blue groups (P>0.05). Furthermore, there is no difference between the Reciproc and PTUR files regarding the amount of remaining RCFM (P>0.05). The Reciproc file removed the RCFM in a shorter time than the other groups (P<0.05). However, there is no difference among the other three groups (P>0.05).
    Conclusions
    None of the tested files could completely remove the RCFM. Under the limitation of this study, the files with shape memory (Reciproc and PTUR files) exhibited better performance than the files with reduced shape memory (Reciproc Blue) and controlled memory (HyFlex CM) in removing the RCFM.
    Keywords: Root canal filling , Retreatment , Endodontics
  • fatemeh koohpeima, Fereshteh Sobhnamayan, Masoud Esfandiari, Saba Siabani Pages 559-566
    Statement of problem: It is crucial to select the best dental material for restoration of teeth that undergo vital pulp therapy after endodontic treatment.
    Objectives
    Adhesion of composite resin and endodontic pulp capping material affect the outcome of treatment. The aim of the present study is to
    evaluate the adhesion of two different composite resins to calcium enriched mixture (CEM).
    Materials and Methods
    We prepared a total of 60 cylindrical acrylic blocks that contained a central hole (4 mm diameter and 2 mm height) CEM cement was mixed according to the manufacturer’s instructionsand introduced into the holes. We stored 30 specimens for 3 days and the remaining 30 specimens were stored for 7 days at 37ºC. The specimens were further divided into 2 subgroups based on the composite resins that we used. One subgroup of specimens was restored by Z350 (3M, ESP, St. Paul, MN, USA) nanohybrid and the other restored by P90 (3M, ESP, St. Paul, MN, USA) silorane based composite. Shear bond strengths were measured by universal testing machine. Failure modes of the samples were evaluated under a stereomicroscope.
    Results
    At day 3, P90 had significantly higher shear bond strength than Z350 (P=0.001). On day 7, Z350 had significantly higher shear bond strength compared to P90 (P=0.004).
    Conclusions
    Within the limits of the present study, the best results of P90 silorane based composite filling after vital pulp therapy with CEM cement biomaterial were obtained after 3 days, whereas the Z350 nanohybrid composite showed better results on day 7
    Keywords: Calcium enriched mixture , Nanohybrid , Shear bond strength , Silorane
  • Janan Ghapanchi, Maryam Zangoei Boushehri, Abdolaziz Haghnegahdar, Shiva Nayyrain, Hajar Shakibasefat, Maryam Paknahad Pages 567-572
    Statement of the Problem: It is crucial to have sufficient knowledge about inferior alveolar canal variations in mandibular surgeries. Anatomic imaging of
    the mandibular canal prior to surgical procedures such as implant placement and sagittal split osteotomy is essential for achieving the best results and confronting minimal complications.
    Objectives
    The aim of this study was to determine normal variations of the mandibular canal and mental foramen in a selected Iranian population. Material and
    methods
    This cross-sectional study was conducted on 334 cone beam computed tomography (CBCT) of patients , comprising of 119 males and 215 females , aged between 15-75 years (mean age, 45±7.5 years). The prevalence of anterior loop, the level of mandibular canal cortication, and mental foramen variations were recorded on CBCT images.
    Results
    Statistical analysis showed no significant differences in the prevalence of the anterior loop and mental foramen variations in both sides regarding the age and gender (p>0.05). Anterior loop was detected in 90.5% of cases, while accessory mandibular canals were observed in 4.6% of the patients. More than one mental foramen was detected in 5 (4.2%) men and 17 (7.9%) women in the right side and in the left side; this was detected in 11(9.2%) men and 10 (4.7%)
    women. No significant differences were found in the number of mental foramen regarding to gender and age in both sides (p>0.05). A non-significant relationship was observed between the age groups, the gender, and the prevalence of accessory canals. Moreover, statistical analysis did not demonstrate a significant
    relationship between gender and mandibular canal cortication in both sides.
    Conclusions
    This study demonstrated that there were numerous anatomical variations of the mandibular canal, mental foramen and, anterior loop
    Keywords: Cone Beam Computed , Tomography (CBCT) , Mandibular Canal, Mental foramen
  • Abdolaziz Haghnegahdar, Mehrdad Vossoughi, Zahra Teymoorienik, Leila Khojastepour Pages 573-582
    Objectives
    This study aimed to evaluate the efficacy of Kvaal et al.’s method (1995) for dental age estimation of adult individuals in a sample of Iranian population. For this purpose, the accuracy of the regression formulas and M and W-L variables were studied.
    Materials and methods
    Pulp and tooth lengths and widths were measured on 100 digital panoramic radiographs. Then Kvaal’s M and W-L variables were computed and substituted in Kvaal’s formulas to evaluate their accuracies. The efficacy of these two variables in our population was assessed using a k-fold cross-validation technique for regression analysis. Principle component analysis was also performed to develop population-specific dental variables.
    Results
    Applying Kvaal’s regression formulas on multiple teeth in different jaws resulted in highly insensible estimations. In contrast, developing regression formulas based on Kvaal’s M and W-L variables yielded reasonable and sensible estimates especially for younger individuals; standard error of estimate (SEE) values ranged from 6.36-6.80 years. The models based on multiple teeth in different jaws performed similar.
    Conclusions
    For young adults, the M and W-L variables anticipated accuracy rates lower than those of Kvaal’s reference study which were within an acceptable threshold for forensic application (SEE<10 years). Therefore, the two variables and not formulas are proper measurements for forensic age estimation in Iranian young adults. However, underestimation was predominant for the middle age and old age participants
    Keywords: Dental age estimation Kvaal’s, method , Adults , Accuracy , Iranian population
  • Negar Pourhatami, Safoura Sahebi, Shamseddin Ahzan Pages 583-587
    External inflammatory root resorption is a serious complication of a dental trauma, which leads to progressive loss of the tooth structure and destruction of periodontal tissues. Therefore, it represents a challenge in endodontic practice especially in cases of young children with incomplete root development.
    Vital pulp therapy (VPT) is an appropriate technique in the management of immature permanent teeth with partial pulp necrosis. This case report describes the outcome of a successful VPT in an immature traumatized permanent tooth with concurrent associated partial necrosis and external root resorption limited to the coronal part of the root in a 7-year-old boy. The tooth was treated according to the protocol suggested by American Association of Endodontics (AAE), consisted of disinfecting the root canal system beyond the resorptive lesion. Afterwards, mineral trioxide aggregate (MTA) was packed into the coronal portion of the canal and the tooth was restored with composite resin. The radiographic follow-up at 3 months showed arrest of root resorption followed by re-establishment of the periodontal space at 6 and 12 months in the absence of clinical symptoms. The satisfactory outcome of this case suggests that this conservative approach can heal a partially necrotic pulp and create a favorable environment for continued root development, and arrest of the resorptive process
    Keywords: External inflammatory root , resorption, Dental trauma , Mineral trioxide aggregate, Vital pulp therapy